What is the REV wire for..

…on the Android Headunit?

Rev, reverse, backup. They are often labelled on the pink wire. But what is this pink wire for, what to connect it to or even, do you need to connect the pink rev wire for the android head unit to work?

Universal Fit

The universal fit android headunits, like any of our universal fit androids reviewed here have universal wiring connectors. Unlike the custom fit android headunits with their factory style connectors, ISO plugs are supplied with the universals for connecting to either an older vehicle directly or to a manufacturer specific adaptor cable.

Universal ISO system

The ISO system deployed by the universal fit android headunits gives a high degree of flexibility and reduces the need to cut and join wires. This is true from the main speaker and power connections, so these can be plug and play.

Then there is the reversing camera

One of the main selling points for an android headunit is the reversing camera feature. A rear mounted camera and a feed of that video signal to the android headunit will help when backing up a vehicle.

The android headunit switches automatically to the camera view from its android screen when reverse gear is selected. The android headunit knows when to switch by monitoring the reversing light signal. This is what the pick wire on an android headunit is used for.


REV is short for ‘reverse’ and reverse is to indicate the gear selection for travelling backwards or just backing up. REV can be a pink wire on an android headunit, but not always. The colour for REV is not standard so it could be any colour wire. The important thing is that it is either marked REV, reverse or the colour in the installation guide is identified as REV.

What to connect the REV wire to?

Android Headunit Tip

Connect the pink wire to any wire that goes live when reverse gear is selected.

When reverse gear is selected the rear white warning lights are illuminated. The obvious place to connect REV to is the rear light cluster, at the reversing lamp. This position couldn’t really be any further away from the headunit, so it doesn’t sound ideal. But, the camera video cable will run from the rear of the vehicle and the camera power supply can also be taken from the same place as the the pink wire. So pick up power to the backup camera at the rear cluster, reversing lamp and connect the pink wire to this point too.

You will be running the reversing camera video cable from the rear of the vehicle to behind the dashboard. It connects to your android headunit at this point. Also run the Pink ‘backup’ feed at the same time as the camera feed. Some camera cables have an integrated power lead, so follow the instructions supplied with the reversing camera. We also have a guide to connecting the pink wire, the reversing camera wiring and a diagram for your android headunit here.

Finding the reverse signal

If you can’t access the wiring diagram for your vehicle use a 12v meter and test to earth each cable in the rear cluster with a helper in the drivers seat to select reverse. You would expect to see around +12v with reverse selected and 0v when it isn’t selected. Don’t forget you may need the engine running or at least the ignition on to find the signal wire. You can see what is required by watching the reversing lights. If they don’t come on when reverse is selected, you may need to start the engine.

CAN bus error – lamp out error

Problems can appear with CAN enabled vehicles and the lighting circuit and if you get a false message indicating the reversing lamp is faulty, you will need to fit a CAN bus bypass relay.

REV wire on an Android Headunit
The pink wire on an Android Headunit needs connecting to the vehicle for backup camera to work

Other wires in the same series

Wires in the speaker connections series

An android-headunits.com staff blogger. I am a multi-skilled dogs-body and I also make the coffee ☕

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